Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6266202 | Current Opinion in Neurobiology | 2015 | 6 Pages |
â¢Theta-gamma coupling supports memory processes in the entorhinal-hippocampal network.â¢Theta-modulated slow gamma may promote memory retrieval.â¢Theta-modulated fast gamma may facilitate memory encoding.â¢Theta-nested gamma reflects gamma rhythmic inhibition and theta rhythmic excitation.
For decades, theta rhythms (â¼5-10Â Hz) have been thought to play a critical role in memory processing in the entorhinal-hippocampal network. However, recent evidence suggests that successful memory performance also requires coupling of â¼30-100Â Hz gamma rhythms to particular phases of the theta cycle. Recent insights imply ways in which theta-gamma coupling may facilitate transfer of information throughout the entorhinal-hippocampal network. Activating gamma-modulated cell assemblies at a particular theta phase may allow the network to produce a more powerful output by ensuring that distributed cells fire closely in time. I hypothesize that such a mechanism would serve to facilitate either memory encoding or memory retrieval, depending on which type of gamma rhythms are recruited.